Industrial Chemicals– Possible Carcinogen (IARC 2B)
CAS No. 107-06-2
Photo: Wikimedia Commons
IARC Monograph Vol. 71, 1999 (Group 2B)
1,2-Dichloroethane is a clear, colourless, oily liquid with a chloroform-like pleasant odour and volatile properties. It is an important industrial chemical, particularly as an intermediate in the production of polyvinyl chloride.
1,2-Dichloroethane may also be referred to as ethylene dichloride. There are numerous other synonyms and product names; see HSDB for more information.
1,2-Dichloromethane has been classified by IARC as Group 2B, possibly carcinogenic to humans, based on evidence in experimental animals. Studies in mice and rats have shown an increased incidence of tumours at various sites, including the stomach, lung, liver, mammary gland, and uterus. Although excesses of some cancers have been observed in epidemiological studies, study results are inconclusive due to potential exposure to multiple compounds.
In addition, ingestion and/or inhalation exposure to high levels of 1,2-dichloroethane may cause adverse health effects in lungs, kidney, liver, and the nervous system.
1,2-Dichloroethane was not included in other Canadian government chemical listings reviewed.
1,2-Dichloroethane is used primarily in the production of vinyl chloride monomer, which is used to make polyvinyl chloride (PVC). A small quantity of 1,2-dichloroethane is used in the production of compounds including ethylenediamines, tri- and tetrachloroethene, aziridines and various chlorinated solvents used for extraction and cleaning.[3,11]
The use of 1,2-dichloroethane as a lead scavenging agent in gasoline is declining, although the extent of its current use in aircraft fuel is not clear. Historically, 1,2-dichloroethane was used in ore flotation and metal degreasers, as a grain, household and soil fumigant, and as a solvent in textile cleaning and pharmaceutical product processing.
Canadian Production and Trade
Dow Chemical, the only recent major Canadian producer of 1,2-dichloroethane, closed its plant in Fort Saskatchewan, Alberta, in October 2006. The prior closure in 2005 of Canada's last vinyl chloride monomer (VCM) facility in Fort Saskatchewan meant that, by the end of 2006, all 1,2-dichloroethane produced in Fort Saskatchewan was being exported.
Prior to the closures, Canada produced up to 900 kilotonnes of 1,2-dichloroethane per year.
Production and Trade
Import: Mainly from US
134 t of '1,2-dichloroethane (ethylene dichloride)'
t = tonne
Inhalation is the most important route of occupational exposure, although there is potential for ingestion and dermal contact. Occupational exposure occurs mainly in individuals involved in the production of vinyl chloride.[2,5] Fugitive emission from leaks in valves, pipes and connectors may contribute significantly to employee exposures. Because 1,2-dichloroethane is generally produced in a closed system, exposures are minimal except during activities such as quality control sampling, and maintenance procedures like high pressure cleaning and filter changes.
The main source of exposure to 1,2-dichloroethane for the general population is indoor air. 1,2-Dichloroethane has rarely been detected in food and there is low potential for bioaccumulation. Exposure may also occur via consumption of contaminated water, but its fast evaporation from water into air decreases this risk.
The main sources of emissions in Canada have been from the manufacture and distribution of 1,2-Dichloroethane, its use in the production of vinyl chloride,[3,13] and from hazardous waste sites. In the past, household products such as cleaning products, pesticides, and carpet/wallpaper glues contained 1,2-dichloroethane.
Monitoring of Dow Chemical Canada Inc's production and storage locations from 2001-2004, under CEPA's life cycle management requirements, recorded a 34% reduction (3,957 kg) in 1,2-dichloroethane emissions at its Fort Saskatchewan plant and a 54% reduction (1,253 kg) from the North Vancouver facility.
Ambient air surveys conducted from 1988-1990 in 12 Canadian cities across 6 provinces found mean levels of 1,2-dichloroethane ranging from 0.07–0.28 µg/m3. The mean concentration of 1,2-dichloroethane from a 1991 national pilot study of residential indoor air (750 residences,10 provinces) was 1.8 µg/m3. Canadians' total daily intake of 1,2-dichloroethane has been estimated to be 0.43-0.70 µg/kg-body weight/day.
No household products with 1,2-dichloroethane as an ingredient were listed in the U.S. Household Products Database. A search of the National Pollutant Reporting Inventory (NPRI) yielded the following results on current potential for exposure to 1,2-dichloroethane in Canada: